<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>rem+媒体查询</title>
    <style>
      @media screen and (min-width: 320px) {
        html {
          font-size: 25px;
        }
      }
      @media screen and (min-width: 640px) {
        html {
          font-size: 50px;
        }
      }
      * {
        margin: 0;
        padding: 0;
      }
      div {
        text-align: center;
        font-size: 1rem;
        height: 1.5rem;
        background-color: pink;
      }
    </style>
  </head>
  <body>
    <div>购物车</div>
  </body>
</html>
